Light sources of the type comprising, for example, at least one LED are usually supplied through an electronic converter which provides a continuous current at its output. This current can be stable or can vary over time, for example in order to control the intensity of the light emitted by the source (by what is known as a “dimming” function). For example, the current can be controlled in the electronic converter by a control method using pulse width modulation (PWM).
However, the operating conditions can vary between different light sources. For example, there can be variations, which may be significant, in the nominal (or requested) or maximum current, the wavelength of the emitted light, and the like.
A possible solution for this problem is to use LED modules (or “light engines”), each of which comprises an identification element for identifying at least one control parameter of the LED module. In this case, the electronic converter comprises a control circuit which communicates with the identification element and adapts the operation of the electronic converter to the specific operating conditions required by the LED module.
For example, in the simplest case, the identification element can be an impedance (such as a resistor or capacitor) which identifies the supply current required by the LED module.
The identification element can also be more complex and can comprise a control unit such as a microprocessor, which supplies the corresponding data through a digital communication interface.
An “intelligent” identification element (that is to say, one having a digital communication interface) is usually capable of handling a plurality of control parameters (such as control parameters relating to information on the state of the LED module and/or for the dimmer operation) more effectively than a “simple” identification element (that is to say, one having an analog communication interface).
The inventors have observed that there are problems of compatibility between electronic converters and LED modules where the latter are not all of the same type. This is because an electronic converter intended for use with a “simple” LED module cannot recognize an “intelligent” LED module, and vice versa. This means that the correct LED module must be selected for a specific electronic converter, or vice versa, and that, when an electronic converter is replaced by a converter of a different type, all the LED modules must also be replaced.
The inventors have also observed that the use of a single type of LED module is inconvenient. For example, the simpler LED modules are unable to provide some control parameters. A possible solution to this problem could be to add a control unit to each simpler module. However, such a control circuit would be rather costly and would therefore make this solution inefficient.